# BAKERBOlTS L.L.P

December 11, 2009
BYELECTRONIC MAIL Mr. Eddy Lin MC-206, Air QualityDivision, TCEQ P.O. Box 13087 AustinTX78711-3087 elin@tceq.state.tx.us
Re: Chapter 115 Stakeholder Group DearEddy: ONE SHELL PLAZA 910 LOUISIANA HOUSTON, TEXAS 77002-4995
TEL +1713.229. 1234 FAX + 1713.229.1522 www.bakerbotts.com

Jason C. Moore TEL +1 713.229.1723 ABU DHABI AUSTIN BEUING DALLAS DUBAI HONG KONG HOUSTON LONDON MOSCOW NEWYORK PALOALTO RIYADH WASHINGTON

FAX +1 713.229.7723 jason.moore@bakerbotts.com

The Texas Terminal Operators Group appreciates the opportunity to provide informal comments on issues with the degassing rules in 30 TAC Chapter 115. The Group's comments are enclosed. Forfurther information, please do nothesitateto contactme.

Sincerely

# ~c.k**Ja~C~oore** -

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TexasTerminalOperatorsGroup Comments on Chapter 115 DegassingRules

I. INTRODUCTION 

### The Texas Terminal Operators Group ("the Group") appreciates the opportunity to provide informal comments on the revised degassing rules in 30 TAC Chapter 115. Group members own or operate a significant percentage ofthe for-hire industrial storage tanks in the Houston-Galveston-Brazoria ("HOB") area. The Group is comprised of Houston Fuel Oil Terminal Company, Intercontinental Terminals Company LLC, Kinder Morgan LiquidTerminal LLC, LBC Houston LP, Oiltanking Holding Americas Inc., StolthavenHouston Inc., and Vopak LogisticsNorthAmericaInc. In general, as a result ofrevisions to certain tank degassing rules in Chapter 115 that became effective January 1, 2009, certain clarifications and/or rule modifications are necessary to ensure the consistent application of the degassing rules and to allow Group members to better ensure compliance with the rules. Toward that end, the Group offers the following specific comments ontherevised degassing rules. II. SPECIFICCOMMENTS A. Rule Clarifications 

### At the November 16, 2009 stakeholder meeting, Texas Commission on Environmental Quality ("TCEQ") staff invited comment on certain rule clarifications. The Group's comments are as follows. 1. Definitions of"Degassing" and "Venting" 

### Section 115.542(a)(6) sets forth the control requirements for venting to the atmosphere when a tank is degassed or cleaned. As the rules are currently written, there is uncertainty as to when the degassing control requirements are triggered. The existing storage tank rules in 30 TAC Chapter 115 (Subchapter B, Division 1) set forth the control requirements for storage tanks up to and including when a floating roofhas landed. There is uncertainty as to whether Section 115's degassing rules are triggered once a floating roofhas landed and stands idle, but no active degassing or cleaning activities have begun. In such a situation, the tank is neither controlled nor forcibly ventilated and would only emit small amounts ofbreathing losses, if any, ofVolatile Organic Compounds ("VOCs") as a result of standing idle. The rules in Subchapter Bappear to apply in sucha situation. Forexample, 30 TAC § 

### 115.112(d) (2)(H) sets forth control requirements that specifically include situations where a floating roofhas landed and is supportedbyleg supports. Additionally, there is uncertainty regarding the applicability of the 30 TAC Chapter 115, Subchapter F, Division 3rules when storage tanks are degassed to a control device but are not subsequently opened and ventilated for cleaning or personnel entry. Such degassing operations may be performed for floating roof landings as required by New Source Review ("NSR") permits when tank cleaning is not deemed necessary, or from rooflanding events that

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### are otherwise authorized by degassing a tank that will be refilled without any tank cleaning involved. The Group therefore suggests that Section 115.542be revisedto statethat Chapter l15's degassing requirements apply only to degassing activities performed (a) in preparation of cleaning for a planned product change in service, or (b) in preparation for personnel entry for interior inspection or maintenance. The rule should make clear that it does not apply to vessel degassing events withno subsequentcleaning ortankentry. Further, the Group suggests that the rules be revised to make clear that the degassing rules do not apply until a tank is physically connected to a control device for the purpose ofdegassing, or, in the case offacilities with permanent degassing control equipment, until the owner or operator takes action to initiate the cleaning process. Prior to such time, the general control requirements for storage tanks in Section 115, Subchapter B, continue to apply and would sufficiently address the storage of any VOCs until the tank is opened for active ventilation, degassing, orcleaning. In addition, the Group recommends that the Section 115.542 be revised to reflect that, for purposes of this rule, the term "vented to the atmosphere" includes only active ventilationusing devices such as fans and other air-movers designedto (a) clear atank's internal vapor space ofpotentially hazardous atmosphere and (b) provide fresh air necessary for safe confined-space entry by personnel. This term should not include uncontrolled floating roof storage tanks that are merely standing idle, as these tanks are adequately addressed by the existing storage tankrules inChapter 115, SubchapterB. 2. Whento Startand StopTaking 12-HourVOC Concentration Measurements (a). No measurements shouldberequired once a tankreaches 17,500 ppmorless, oris below25 percentoftheLEL 

### Section 115.542(a)(6) requires that "VOC concentrations must be measured once every 12 hours ifthe storage tank or transport vessel is vented continuously to the atmosphere, and upon restart ofthe degassing and cleaning operation ifventing to the atmosphere has been suspended for more than four hours." This provision also provides that "[w]hile venting to the atmosphere, measurements mustcontinue until five consecutive readings ofVOC concentrations collected at 12 hour intervals are measured to be less than 34,000 ppm or less than 50% ofthe LEL." 

### Once the controlled portion of degassing is complete, a tank is then typically prepared for interior cleaning and maintenance personnel confined-space entry by actively ventilating the tank's vapor space with fresh air, thereby removing a potentially hazardous atmosphere from the tankbefore any entry is allowed. Since the January 2009 effective date ofthe most recent revisions to the Chapter 115, SubchapterF, Division 3degassing rules, Group members have beencollectingthe required 12-hour tank VOC concentration readings for storage tanks that have been degassed. These actual measurements demonstrate that when a storage tank has been successfully degassed to

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below 34,000-ppmv (or to below 50-percent LEL) and the tankhas no significantresidual liquid heel or bottom sludge, thatthe tank's interior VOC concentration is typically very low within a few hours ofbeginning active vapor space ventilation, andthat itwill remain low due to the lack ofany significantproductheel insidethetank. In such instances, the existingrule requirementto collect any additional VOC concentration measurements results in an unnecessary use of resources, and also increases costs for those companies that hire third-party contractors to perform and documentthese VOC vapor spacereadings. Accordingly, Group members propose that Section §115.542(a)(6) be revised to make clear that no additional VOC concentration measurements are required once (a) a tank has been washed and degassed or has been deemed safe for entry, and (b) the tank is documented to be below 17,500-ppmv VOC or less than 25-percent of the LEL. Providing these specific conditions and VOC levels within the rule will allow Group members to more effectively utilize their resources while also providing the TCEQ with assurance that a degassed storage tank has satisfiedthe requirement for VOC controlbelow34,000-ppmv orbelow 50-percentLEL. (b). Avapor space turnover requirement is unnecessarily burdensome At the November 16, 2009 stakeholder meeting, TCEQ staffindicated that one option under consideration is the addition of a vapor space turnover requirement prior to completing degassing. This requirement would be unnecessarily burdensome because it would require operators to potentially run degassing equipment when vapors in the tank are already belowthe 34,000ppmvthreshold for VOCs.
In addition, such arequirement would result in excess assist fuel being consumed to support the combustion in the control device during periods oflow tank vapor space VOC concentrations. Additional combustion by-product emissions (nitrous oxides and carbon monoxide) will also be generated as a result ofoperating degassing equipment when a tank is below 34,000 ppmv ofVOCs, which is undesirable in ozone non-attainment areas such as the HGB area. B. Demonstrating ControlEfficiency Section 115.541(a)(1)(B) provides that "[t]he vapor control system must maintain a control efficiency ofat least 90%." There is uncertainty as to how regulated entities are to demonstrate compliance with this provision. Much ofthis uncertainty arises from the fact that while the rules specify a minimum 90% control efficiency and several "ApprovedTestMethods" are listed, there is no specific requirement within these regulations to perform actual stack testing. Itis also unclear when and how often regulated entities must test the control efficiency oftheirvapor control systemsused indegassing. Group memberstypically do notperformtank degassingthemselves. Rather, they hire third party tank degassing contractors that move skids loaded with degassing equipment from facility to facility. It would be highly impractical to require each contractor to perform stack testing each time it brings equipment onsite to degas a tank. Requiring repeated stack testing would also unnecessarily divert manpower resources, result in significant operational delays, and cause additional expense.
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### BAKERBOlTS LL.P Moreover, a wide variety ofvapor control devices are utilized for controlled tank and transportation vessel degassing operations. Fixed and portable flares, fixed and portable thermal oxidizers, carbon adsorption units, portable internal combustion engines, and portable vapor refrigeration/condensation units are used to perform controlled degassing operations at Group memberfacilities. The Group therefore suggests that Section 115.541 be revised to expressly provide thatregulated entities may complywiththis provisionbyproviding a one-time stacktest report for each control device used during degassing operations. This would allow Group members and contractors to effectively and efficiently demonstrate compliance with the rule by showing the required efficiency level for degassing equipment without the cost and burden of repetitive stacktesting eachtime degassing is performed. Similarly, the Group suggeststhatthe rules make clear that control devices that have already demonstrated compliance with the 90% control efficiencyunder Section 115.545 neednotbe retested underthe forthcoming rules. The Group also suggests adding a requirementthat TCEQ approve the stacktests requiredunderthis sectionto betterenable tank owners and operators to ensure compliance with the rules. The Group suggests thatthe source tests required underthese rules shouldbe required to be submittedto andapprovedby TCEQ within 60 days. The Group further suggests that the rules be revised to clarify how compliance with the required control efficiency should be demonstrated for (a) non-enclosed flares, which can not be sampled after control; (b) for vapor refrigeration/condensation units, which condense vapors back into liquid form but do not destroy any VOC in the process; and (c) for "closed loop" tank degassing configuration, where a return low VOC stream is injected back into the tankfor additional treatment. C. Approved TestMethods Section 115.545 enumerates several testmethods for demonstratingthe emissions specifications and control requirements in sections 115.541 and 115.542. There is uncertainty regarding the various test requirements and methodologies necessary to demonstrate compliance withthe emission specifications and minimum acceptable VOC destruction efficiencies. Due to significant differences in the types ofcontrol devices used for degassing operations, the current list ofapprovedtest methods cited in the current regulations is incomplete. This incomplete list oftest methods, and the lack offlexibility in adopting alternative methods, results in additional complexity and increased cost in performing testing. Furthermore, in the case of thermal oxidizer testing, using the listed test methods could actually create safety concerns iftesters are requiredbythe TCEQto measure stackvelocity directly. Specifically, the Group requests that Test Method 19 (40 CFR 60, Appendix A) be adopted as an approved method and is listed in section 115.545 so that it may be used in compliance testing performed in support of sections 115.541 and 115.542. Test Method 19 allows testing companies to calculate exhaust flow rates based on the measured fuel flow and oxygen concentrations, and has been used extensively in past stack emissions testing. Further, 30 TAC § 117.8000 (Stack Testing Requirements), allows the use of Test Method 19 for determining exhaust gas flow rates for certain testing required under the agency's Chapter 117 rules [see Section 117.8000(c)(5)]. In addition, the TCEQ Air Permits Division has proposed
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that Test Method 19 be applied for exhaust flow rate determinations from internal combustion engines when they are used as a control device for planned maintenance activities under the model draftMSS permit. The Group also requests that section 115.545 be modified to allow the use of other approved test methods that are not specifically cited within the degassing regulation, providedthese testmethods are approved by the executive director. Such flexibility is necessary giventhe widevariety ofcontrol equipmentused for degassing operations. Until these rules can be modified, the Group requests that TCEQ issue interpretive guidance clarifyingthatregulatedentities mayuse othertestmethods not specifically enumerated in Section 115.545 in circumstances where such test methods are more appropriate. This would provide regulated entities with flexibility in performing the most appropriate testing to comply with Section 115'semissions specifications and control requirements. D. Notification Requirements TCEQ staff have invited comment on whether the degassing rules should be revised to include a requirement that regulated entities provide advance notice of planned degassing orcleaning activities inthe HGB area. The Group opposes sucharequirement. A notification requirement is unnecessary given that any unauthorized tank degassing event that exceeds a reportable quantity must be reported to TCEQ in advance pursuantto the existingMSS rules in 30 TAC 101, SubchapterF. Section 101.211(a)provides: The owner or operator ofa regulated entity conducting a scheduled maintenance, startup or shutdown activity shall notify the commission office for the region in which the regulated entity is located and all appropriate local air pollution control agencies withjurisdiction at least ten days prior to any scheduled maintenance, startup or shutdown activity that is expected to cause an unauthorized emission that equals or exceeds the reportable quantity (RQ)

. . .by emissions point in any 24-hour period

. . . . Ifnotice cannot be given ten days prior to a scheduled maintenance, startup or shutdown activity, notification must be given as soon as practicablepriorto the scheduled activity. The existing rules therefore already provide for advance notice to TCEQ ofany significantunauthorizedtankdegassing activity. A notification requirement is also burdensome given the number of degassing activities owners and operators typically perform in a givenyear. Group members often conduct more than 60 degassing or cleaning events per year. Requiring regulated entities to provide advance notice of each planned degassing or cleaning activity is unnecessary and highly burdensome. As such, a notification requirement would add little value for the burden it would place onregulated entities.

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E. Registration Requirement TCEQ staffhave also invited comment onwhetherto revise the degassing rules to require registration ofportable control equipmentused inthe HGB area. As noted above, Group members-aswell as otherfacilities inthe area-typicallyhire thirdparty contractorsto perform degassing or cleaning activities. The Group supports a simple and efficient registration requirement for these contractors. The Group further supports the creation ofa list ofdegassing contractors specifically certifiedbythe TCEQ. However, because degassing activities are typically performed by third party contractors, the Group opposes any requirement that facility owners or operators be required to registerwith the TCEQ orbe liable for any failure ofathird party contractorto comply with any registrationrequirement. F. ComplianceDeadline Several ofthe rule revisions under consideration would require modifications to Group members' existing equipment, particularly permanent control devices. As aresult, ifany rule revisions are approved which would require the modification of existing equipment, the Group requests that the TCEQ provide a reasonable deadline to implement the regulatory changes. The Group therefore suggests the following timeframe for compliance activities involving modifications to existing equipment: (a) ten years for actions thatrequire atank to be placed out ofservice to make the required upgrades, and (b) one year for actions that involve non-tankupgrades.

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